diff --git a/libavformat/flvdec.c b/libavformat/flvdec.c
index d2b2b44ffb..f9eefb197d 100644
--- a/libavformat/flvdec.c
+++ b/libavformat/flvdec.c
@@ -176,7 +176,7 @@ static int flv_read_packet(AVFormatContext *s, AVPacket *pkt)
             case 0: if (flags&2) st->codec->codec_id = CODEC_ID_PCM_S16BE;
                     else st->codec->codec_id = CODEC_ID_PCM_S8; break;
             case 1: st->codec->codec_id = CODEC_ID_ADPCM_SWF; break;
-            case 2: st->codec->codec_id = CODEC_ID_MP3; break;
+            case 2: st->codec->codec_id = CODEC_ID_MP3; st->need_parsing = 1; break;
             // this is not listed at FLV but at SWF, strange...
             case 3: if (flags&2) st->codec->codec_id = CODEC_ID_PCM_S16LE;
                     else st->codec->codec_id = CODEC_ID_PCM_S8; break;